We cannot doubt the existence of an ultimate reality. It is the universe forever masked. We are a part of it, and the masks figured by us are the universe observing and understanding itself from a human point of view.

By convention there is color, by convention sweetness, by convention bitterness, but in reality there are atoms and the void, announced Democritus. The universe consists only of atoms and the void; all else is opinion and illusion. If the soul exists, it also consists of atoms.

— Edward Robert Harrison

In Masks of the Universe: Changing Ideas on the Nature of the Cosmos (1985), 55.

In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion.
(1987) -- Carl Sagan